Retaining walls can be both functional and decorative and range from small gardening applications to large-scale construction projects. Such walls are typically used to facilitate the formation of horizontal surface areas by providing a generally vertical barrier behind which backfill may be deposited. Such walls can also used reduce erosion and slumping in embankments. Retaining walls can be constructed of a variety of materials having a variety of shapes. Some retaining walls have been constructed from wood timbers, while others have been constructed from rocks such as limestone of fieldstones. Still others have been constructed of manufactured concrete blocks. A drawback to existing concrete retaining wall blocks is that production, shipping, and installation is limited due to their facing-area to block-weight ratio.